Method of coating a substrate with a catalyst component

Abstract

A method of coating a substrate with a liquid comprising a catalyst component, which substrate comprises a plurality of channels, wherein the method comprises: (a) holding the substrate vertically; (b) introducing the liquid into the substrate through the open ends of the channels at a lower end of the substrate; and (c) after the lower end of the substrate has been part-filled with the liquid, applying a vacuum to the open ends of the channels at the upper end of the substrate while introducing the liquid into the substrate.

1 - 18 . (canceled) 
     
     
         19 . An apparatus for coating a substrate with a liquid comprising a catalyst component, which substrate comprises a plurality of channels, wherein the apparatus comprises:
 (a) a substrate holder for holding the substrate vertically;   (b) a piston for introducing the liquid into the substrate through the open ends of the channels at a lower end of the substrate;   (c) a vacuum triggering device for triggering a vacuum when the lower end of the substrate has been part-filled with the liquid;   (d) a vacuum generator for applying a vacuum to the open ends of the channels at an upper end of the substrate.   
     
     
         20 . The apparatus of  claim 19 , wherein the substrate holder comprises at least one inflatable collar for contacting an exterior surface of the substrate. 
     
     
         21 . The apparatus of  claim 20 , wherein the substrate holder comprises a housing, and the at least one inflatable collar is supported by the housing. 
     
     
         22 . The apparatus of  claim 20 , wherein the at least one inflatable collar has a square or rectangular cross section. 
     
     
         23 . The apparatus of  claim 21 , wherein the piston is a reciprocating piston within the housing. 
     
     
         24 . The apparatus of  claim 23 , wherein the housing comprises a delivery chamber having a displacement volume, and wherein the reciprocating piston is able to move from (i) a first position, where the piston is retracted and defines the displacement volume of the delivery chamber, to (ii) a second position, where the piston abuts a lower end of the substrate. 
     
     
         25 . The apparatus of  claim 19 , wherein the piston has a piston face that comprises a polymer, which is a polyester. 
     
     
         26 . The apparatus of  claim 24 , wherein the housing comprises a valve in the wall of the housing. 
     
     
         27 . The apparatus of  claim 19 , wherein the vacuum triggering device comprises a timer or a servo motor coupled to a sensor for position feedback of the piston. 
     
     
         28 . The apparatus of  claim 19 , wherein the vacuum triggering device is electrically coupled to the vacuum generator. 
     
     
         29 . The apparatus of  claim 19 , wherein the vacuum generator comprises a funnel for receiving an upper end of the substrate. 
     
     
         30 . The apparatus of  claim 19 , wherein the vacuum generator comprises a seal for forming a sealing engagement with an upper end of the substrate. 
     
     
         31 . The apparatus of  claim 19  further comprising a pick-and-place device for inserting the substrate into the substrate holder.